Invert dependency between sled-agent-types and illumos-utils

[jgallagher]

Both @bnaecker and @zeeshanlakhani recently bumped into issues where the fact that sled-agent-types-versions depends on illumos-utils caused pain, because we needed to add or change types that are defined or consumed by illumos-utils, but those types appear in the sled-agent API and therefore also need to be versioned. We can't put them in sled-agent-types-versions because that creates a cycle between the two crates, but putting them in illumos-utils means they can't (easily) be versioned.

We talked about two possible solutions to this:

1. Add a new *-types-versions + *-types crate that both illumos-utils and sled-agent-types-versions can depend on. [multicast] M2P forwarding, OPTE port subscription, and sled-agent propagation #10070 starts down this path.
2. Invert the dependency: if illumos-utils could depend on sled-agent-types instead of the other way around, we can put the types in sled-agent-types-versions as we'd prefer for versioned types.

This PR implements the second of those, but I'm not totally sold it's the right way to go - maybe it would be cleaner to have a lower-level types crate shared by both. I did want to see how painful it was, and it wasn't too bad.

My gut feeling is that the changes here fall into three categories:

1. Definite win: it moves definitions of types that appear in the sled-agent API out of illumos-utils and into sled-agent-types-versions, allowing them to be cleanly versioned in the future. (Svc, SvcState, ZpoolHealth)
2. Seems fine either way: From impls converting between illumos-utils types and sled-agent types now live in illumos-utils instead of sled-agent-types-versions (AttachedSubnet, AttachedSubnetKind, SvcsResult, DatasetProperties)
3. Seems slightly worse but I could live with it: The one place sled-agent-types used functionality from illumos_utils that didn't make sense to move was OmicronZoneConfig::zone_name(), which calls a function in illumos_utils to construct a zone name. I moved this to an OmicronZoneConfigExt extension trait defined by illumos_utils; I don't love this but on balance I think it's worth taking to get point 1?

[bnaecker]

This is great! Much smaller than I feared.

[bnaecker]

I agree with replacing FromStr. That looks like it's parsing the CLI tool output format.

[zeeshanlakhani]

I do think this limits the complexity of solution #1. As we discussed in chat, its seems that much of illumos-utils (excepting zone naming) it mainly targeting the sled-agent context. Nonetheless, it seems like the original goals of illumos-utils was somewhat murky and that it was meant to be more general?

Nonetheless, this is a nice, focused PR, and helps us in the now.